Fig. 3. (A) Typical breathing pattern obtained during rest (pre-exercise) and exercise in V. mertensi. (B) A spirogram for rest (open symbols) and exercise (closed symbols) that shows the changes in volume and timing that occur with exercise. Note that each breathing cycle starts with expiration (downward deflection), followed by an inspiration and a post-inspiratory pause. Values are mean ± 1 S.D. (N=5).